A forming die includes: a lower forming die having a bottom part and a side wall part; an upper forming die that is movable toward the bottom part of the lower forming die along an axis parallel to the side wall part of the lower forming die; and a push-in die that is movable toward the bottom part of the lower forming die along the axis between the side wall part of the lower forming die and the upper forming die.

A forged crankshaft manufacturing apparatus processes a forged blank with no flash. The forged blank includes at least one rough crank arm having an excess portion protruding from an outer periphery of a side portion thereof. The manufacturing apparatus includes a first die and a second die paired with each other, a retaining device, and a moving device. The first die and the second die bend or crash the excess portion. The retaining device retains at least one of the rough journals or at least one of the rough pins such that a rough pin decentering direction is perpendicular to a reducing direction in which the first die and the second die apply force for reduction. The moving device supports the retaining device such that the retaining device is movable in the reducing direction.

An apparatus for manufacturing a forged crankshaft includes a pair of upper and lower dies and a first tool. The pair of dies deforms first excess portions and thereby thickens both side portions of a rough crank arm, in a region near a rough pin adjacent thereto. The first tool is fitted in an open space made in the pair of dies, and is capable of coming into contact with a rough-journal-facing surface of the rough crank arm, except the side portions in the region near the adjacent rough pin. The first pair of dies and the first tool have first guides to guide the first tool from a retracting position to a contacting position. The first guides include a first guide disposed on at least one of an upper surface and a lower surface of the first tool.

A steering rack includes a rack shaft (10), a plurality of rack teeth (11a) formed on the rack shaft and each having a tooth trace inclined with respect to a first direction perpendicular to an axial direction of the rack shaft, and a dummy tooth (33a) aligned with the rack teeth and formed on the rack shaft. The dummy tooth (33a) is non-uniformly formed in a second direction parallel to the tooth trace of the rack tooth (11a).

A method for texturizing a workpiece uses a die assembly installed within a press having a press ram. The method includes (a) delivering the workpiece onto a centre die plate; (b) forcing the press ram against an upper die plate mounted above the centre die plate to descend a first contact surface associated with the upper die plate and a plurality of blades mounted to the upper die plate toward the centre die plate; (c) actuating horizontal movement of the blades; (d) driving the blades down into the workpiece; and (e) contacting the first contact surface to a second contact surface associated with the centre die plate to descend the centre die plate in unison with the upper die plate.

Provided are a manufacturing method and manufacturing device that allow the depth of rack teeth to be adequately maintained across the axial direction. A stepped surface (47) is provided on one surface in the axial direction of a pressure punch (46) that moves together with a teeth-forming punch (32). The teeth-forming punch (32) is displaced downward and rack teeth are formed on the upper surface of an intermediate material (23). At the same time, the surface on the end in the axial direction of the intermediate material (23) is pressed in the axial direction by a movable die (41a) due to the engagement between the stepped surface (47) and the surface on the other side in the axial direction of the movable die (41a).

A method for texturizing a workpiece uses a die assembly installed within a press having a press ram. The method includes (a) delivering the workpiece onto a center die plate; (b) forcing the press ram against an upper die plate mounted above the center die plate to descend a first contact surface associated with the upper die plate and a plurality of blades mounted to the upper die plate toward the center die plate; (c) actuating horizontal movement of the blades; (d) driving the blades down into the workpiece; and (e) contacting the first contact surface to a second contact surface associated with the center die plate to descend the center die plate in unison with the upper die plate.

In a forming apparatus, journal dies hold and retain rough journal portions of a preform blank therebetween, and reference crank pin die and movable crank pin dies contact rough crank pin portions thereof. In this state, the journal dies and the movable crank pin dies are moved axially toward the reference crank pin die and the reference crank pin die and the movable crank pin dies are moved perpendicular to an axial direction. With this, rough crank arm portions are axially compressed to reduce their thickness to that of crank arms of a forged crankshaft, and the rough crank pin portions are pressed perpendicular to the axial direction to increase an amount of eccentricity to that of the forged crankshaft crank pins. Consequently, it is possible to form a blank for finish forging having a shape generally in agreement with a shape of the forged crankshaft for a three-cylinder engine.

A mold moving device for a forged product forming machine includes a base unit, a transmission mechanism, a guiding member, a mold seat, and a plurality of pressing molds. The guiding member is driven by the transmission mechanism to rotate, and has an outer peripheral surface formed with a plurality of guiding grooves extending in a serpentine manner. The mold seat includes a rotary shaft, a rotating member, and a carrying member on which the pressing molds are mounted. The rotating member is connected to the rotary shaft, and includes a disk body portion and a plurality of projecting rods protruding toward the guiding member. When the guiding member rotates, the guiding grooves respectively engage selected ones of the projecting rods in a manner where the selected ones of the projecting rods respectively slide along the guiding grooves, thereby driving the disk body portion to rotate.

A manufacturing method of press-molded article of the present invention comprises a step of placing a member to be pressed in a press molding apparatus and a step of pressing a flat plate portion of the member to be pressed by bringing a first press portion and a second press portion closer to each other. A first opposing surface and a second opposing surface, while facing to each other, keep in contact with the flat plate portion during pressing. In the press step, a thick part is formed on the flat plate portion by allowing a part of a material of the flat plate portion to flow, in a press direction, into a thickened portion-forming section formed on the first opposing surface. The second opposing surface is moved to the press direction as the flat plate portion is pressed by the first press portion and the second press portion.